Portable power handsaw



Jan. 28, 1930. F. L. CAMPBELL PORTABLE POWER HANDSAW Filed Aug. '7, 1926 2 Sheets-Sheet ATTORNEY WITNESS:

Jan. 28, 1930. F. L. CAMPBELL PORTABLE POWER HANDSAW Filed Aug. 7, 1926 2 Sheets-Sheet 2 a W T 6 W 4 Mw Q M A wt 1 w .l. 5 5L w INVENTOR awn 0.562%

WITNESS:

ATTORNEY Patented Jan. 28, 1930 PATENT OFFICE FRED L. CAMPBELL, OF CHICAGO, ILLINOIS PORTABLE POWER HANDSAW Application filed August 7, 1926. Serial No. 127,853.

This invention relates to certain novel improvements in portable power handsaws and has for its principal object the provision of an improved construction of this character which will be highly efiicient in use.

A further object of this invention is to provide an improved motor operated reciprocating saw adaptedfor hand use.

A further object of this invention is to provide an improved motor operated hand saw which is of simple and relatively inexpensive construction.

A further object of this invention is to provide 'a simple combination and arrangement of parts for reciprocating a motordrivensaw adapted for hand use.

Other objects will appear hereinafter.

The invention consists in the combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings illustrating the preferred form of my invention, and in which:

Fig. 1 is a typical side elevational view of the invention.

Fig. 2 is a fragmentary inner edge view of the invention takensubstantially on line 2-2 of Fig. 1.

Fig. 3 is view taken Fig. 1.

Fig. 4; is view taken Fig. 1.

Fig. 5 is View taken Fig. 3.

Fig. 6 is a fragmentary horizontal sec tional detail view showing a protratcor assembly adapted to 'be associated with the in vention asshown in Fig. 1.

Fig. 7 is a sectional detail view takensubstantially 'on line 77 of Fig.

'To accomplishthevariousob]ects ofmy nvention Iprovide a supporting frame 10 includinga base plate '11 slotted 'longrtudmally as at 12, Fig. "1, and having formed 1n 'lilSlOIla fragmentary sectional detail substantially on line 3-3 of a fragmentary sectional detail substantially on line H of a fragmentary sectional detail substantially on 'line 55 of gitudinal side edge portions 13flongitudinally ext nding g ooves it. This s pp rt g .29 for longitudinal cludes an armature shaft 38. one end of this armature shaft is a bracket E frame includes side frame members 15 merging together as at 16 and defining an elongated opening 18, Fig. l, for reasons hereinafter set forth. This supporting frame further defines a handle portion 19 carrying a socket and plug construction 20 connected in circuit with circuit wires 22.

The side frames 15 define an arcuated bar 23 having a plurality of spaced openings 24 formed therein as best shown in Fig. 1.

The above description concludes the preferred form of constructionof-the supporting frame embodied in this invention and this supporting frame is adapted to pivotally support the driving means A which operates the reciprocatory saw 13. Included as a part of this driving means is acarriage [base 25 supported by a structure 26 defined by guide plates 27 and 28, the latter lbeing-of a length greater than the length of each of these guide plates defines longitudinally extendinggrooves 29 in their opposite edge portions. The structure .26 is supported by a portion 26of the supporting frame 10 and is pivotally connected to this portion 26 through the medium of a .pintle 27. The guide plates 27 and 28 :merge together as at 30 and define an extended portion 31 carrying a spring controlled pin .32 which is adapted for engagement 24. Adapted for reciprocationlongitudinally of the guide plates 27 and 28 is-a carriage 33. This carriage 33 has its opposite correspond ing edge portions 34: confined in the grooves carriage defines opposite racks 35 Fig. 1. The carriage 33 carries the saw blade-36 and this saw blade 36 is detachably connected to the carriage 33 through the medium of bolts and wing nuts 37. The saw blade 36 is adapted to reciprocate through the slot '12 as best shown-in Fig. 1.

The means for reciprocating thesaw blade includes an electrically driven motor C connected'to the plugof the plug and socket construction 21 through the medium of circuit wires D. Thiselectrically driven motor in- Mounted upon h g it en Portion 39 connec -ed te hs the former and in any one of the openings 1 movement therein. This structure 26 as at Fig. 3. Adapted for alternate meshing relation with respect to the racks 35 is a driven gear 41 carried by an operating shaft 42 having a ball shaped end portion 43 rotatably engaged in a similarly shaped socket 44 formed in the bracket E. The socket 44 is formed by pressing out a portion of the bracket E and after the ball 43 is mounted therein the edges of the bracket surrounding the ball are peened over so as to retain said ball. This shaft 42 is operatively connected to the shaft 38 of the motor C through the medium of a train of gears 45.

Means is provided for alternately moving the gear 41 into meshing relation with the racks 35. This means includes a supporting strip 46 carried by the guide plates 27 and 28 and secured thereto through the medium of securing elements 47. This supporting strip 46 ivotally carries a shifting lever 47 as at 48 Fig. 1. One end portion 49 of this shifting lever 47 is connected to the end portion 50 of the shaft 42 and the opposite end portion 51 of this shifting lever is curved upwardly, Fig. 1, and carries a roller 52. This roller 52 is adapted to operatively engage the edge 53 of a cam 54. This cam 54 is connected to a shaft 55 and is operatively connected to the motor 38 through the medium of a train of gears 56.

The above description concludes the preferred form of construction of my reciprocatory power driven hand saw and the operation of the same is as follows:

When the motor C is operated transmission is imparted to the shaft 42 through the medium of the train of gears 45 and causes the gear 41 to operate. trated the saw and its carriage in their extreme outer position with the gear 41 in position about to be shifted from the upper rack to the lower rack of the racks 35. This shifting is accomplished through the medium of the shifting lever 47 and cam 54. As this cam 54 is rotated through the medium of the motor C and train of gears 56 the low edge portion 54 of the cam will be brought in the path of the roller 52 and when this roller 52 engages the low edge portion 54, a spring 55' will retain it in such engagement and the shifting lever 51 will be pivoted about its pivot 48 shifting the gear 41 in a downward direction into meshing relation with the lower rack of the racks 35. The gear in this posi tion will cause the carriage 33 to move the saw blade 36 in an outward direction. This movement in this direction continues until the roller 52 engages the high edge portion 53' of the cam 54 at which time the lever 51 will be pivoted in an opposite direction about its pivot 48 shifting the gear 41 into meshing relation with the upper rack of the racks 35 at which time the carriage will be caused to move the saw blade in an opposite direction.

In Fig. 1 I have illus- At this time it is pointed out that the ball 43 and socket 44 permit the shaft 52 to be tilt ed a sufiicient distance to engage the teeth of the gear 41 into engagement with the teeth of either of the racks 35 and that the teeth of the gears 45 of the train of gears 45 are so constructed that they will remain in meshing relation during shifting of the gear 41.

To control the electrical circuit to the motor C I have provided a suitable switch structure 21 which includes two push buttons 22 whereby by pushing one button the circuit will be broken and by pushing the other button the circuit will be closed. This switch structure 21 is only diagrammatically illustrated in the drawings and not included as a part of this invention as it is known that any well known type of switch structure may be substituted for that illustrated in the drawings.

\Vhcn the saw blade 36 is being reciprocated through the driving means herein referred to, it is manifest that manipulation of the saw proper manually accomplished by tirn'ily grasping the handle 19 and when thus grasped shifted over the work upon by the saw blade 36.

As herein described I have provided means for adjusting the saw blade 36. This is acto be operated complished by adjusting the spring con trolled pin 32 in any one of the openings 24, it being pointed out that the carriage base 25 being projected through the opening 18 is permitted to pivot with the carriage when the saw blade 36 is adjusted in various angular positions.

To facilitate expeditious adjustment of the saw blade 36 I have provided on the guide plate 28 a handle knob 28 whereby by grasping this handle caused to pivot about the pintle 27'.

In Figs. 6 and 7 I have illustrated an attachment for the supporting frame 10 whereby the operator of the saw may adjust the same for angular cutting through the work. attachment includes a protractor F defined by a face plate 58 carried by a guide arm 59 defining a guideway 60 into which projects opposite ribs 61 adapted to be slidablyreceived in the grooves 14. This face plate 58 has graduations 62 formed thereon and is movably associated with the guide arm 67 through the medium of lateral tongues 63 which engage in grooves 64 formed in the face plate and in attachment plates 65, Fig. These attachment plates 65 are connected to the face plate through the medium of suitable rivets 66. The indicating fingers 67 have tapered end portions 68 facilitating determining the angular position in degrees of the face plate 58 with respect to the guide arm 59. The guide arm 59 is secured in the desired angular position with respect to the face plate 58 through the medium of thumb screws 69, Fig. 7.

knob the structure 26 will be This It is intended that the guide arm be of such length that when it is received by the base 11 the protractor construction will extend forwardly of the saw so that when the guide arm 59 is held against movement over the work the saw structure, when moved, will operate upon the work and saw through the work at the desired angular direction as is predetermined by adjusting the guide arm with respect tothe face plate.

Vhile I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variations and modification without depart ing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claim.

Having thus described my invention, What I claim as new and desire to protect by Letters Patent is:

In a device of the class described, a frame, a saw carrying carriage reciprocally mounted therein, means for reciprocating said carriage including coextensive oppositely disposed aligned racks, a shaft, a shifting lever rockably mounted on said frame, one end of said shaft being rotatably ournaled in said shifting lever, a pinion on said shaft adapted to selectively engage said racks, a ball formed on the other end of said shaft, a member carried by said frame having a socket formed therein adapted to receive said ball, means for rotating said shaft including an electric motor and a gear train, said gear train engaging said shaft adjacent the ball carrying end thereof, a cam, means for driving said cam from the shaft of said motor, said shifting lever having a cam follower thereon at the end opposite the end carrying said shaft, said. follower engaging said cam whereby said shaft may be rocked in order to selectively engage said pinion with said racks.

In testimony whereof I aflix my signature.

FRED L. CAMPBELL. 

